#ifndef __I386_KERNEL_SEGMENT_H__
#define __I386_KERNEL_SEGMENT_H__

#include "i386/segment.h"

// /*
//  * The layout of the per-CPU GDT under Linux:
//  *
//  *   0 - null
//  *   1 - reserved
//  *   2 - reserved
//  *   3 - reserved
//  *
//  *   4 - unused			<==== new cacheline
//  *   5 - unused
//  *
//  *  ------- start of TLS (Thread-Local Storage) segments:
//  *
//  *   6 - TLS segment #1			[ glibc's TLS segment ]
//  *   7 - TLS segment #2			[ Wine's %fs Win32 segment ]
//  *   8 - TLS segment #3
//  *   9 - reserved
//  *  10 - reserved
//  *  11 - reserved
//  *
//  *  ------- start of kernel segments:
//  *
//  *  12 - kernel code segment		<==== new cacheline
//  *  13 - kernel data segment
//  *  14 - default user CS
//  *  15 - default user DS
//  *  16 - TSS
//  *  17 - LDT
//  *  18 - PNPBIOS support (16->32 gate)
//  *  19 - PNPBIOS support
//  *  20 - PNPBIOS support
//  *  21 - PNPBIOS support
//  *  22 - PNPBIOS support
//  *  23 - APM BIOS support
//  *  24 - APM BIOS support
//  *  25 - APM BIOS support
//  *
//  *  26 - ESPFIX small SS
//  *  27 - per-cpu			[ offset to per-cpu data area ]
//  *  28 - stack_canary-20		[ for stack protector ]
//  *  29 - unused
//  *  30 - unused
//  *  31 - TSS for double fault handler
//  */

#define GDT_ENTRY_TLS_MIN	6
#define GDT_ENTRY_TLS_MAX 	(GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)

#define GDT_ENTRY_DEFAULT_USER_CS	14

#define GDT_ENTRY_DEFAULT_USER_DS	15

#define GDT_ENTRY_KERNEL_BASE	12

#define GDT_ENTRY_KERNEL_CS		(GDT_ENTRY_KERNEL_BASE + 0)
#define GDT_ENTRY_KERNEL_DS		(GDT_ENTRY_KERNEL_BASE + 1)

#define GDT_ENTRY_TSS			(GDT_ENTRY_KERNEL_BASE + 4)
#define GDT_ENTRY_LDT			(GDT_ENTRY_KERNEL_BASE + 5)

#define GDT_ENTRY_PNPBIOS_BASE		(GDT_ENTRY_KERNEL_BASE + 6)
#define GDT_ENTRY_APMBIOS_BASE		(GDT_ENTRY_KERNEL_BASE + 11)

#define GDT_ENTRY_ESPFIX_SS		(GDT_ENTRY_KERNEL_BASE + 14)
#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8)

#define GDT_ENTRY_DOUBLEFAULT_TSS	31


/*
 * The GDT has 32 entries
 */
#define GDT_ENTRIES 32

/* The PnP BIOS entries in the GDT */
#define GDT_ENTRY_PNPBIOS_CS32		(GDT_ENTRY_PNPBIOS_BASE + 0)
#define GDT_ENTRY_PNPBIOS_CS16		(GDT_ENTRY_PNPBIOS_BASE + 1)
#define GDT_ENTRY_PNPBIOS_DS		(GDT_ENTRY_PNPBIOS_BASE + 2)
#define GDT_ENTRY_PNPBIOS_TS1		(GDT_ENTRY_PNPBIOS_BASE + 3)
#define GDT_ENTRY_PNPBIOS_TS2		(GDT_ENTRY_PNPBIOS_BASE + 4)

/* The PnP BIOS selectors */
#define PNP_CS32   (GDT_ENTRY_PNPBIOS_CS32 * 8)	/* segment for calling fn */
#define PNP_CS16   (GDT_ENTRY_PNPBIOS_CS16 * 8)	/* code segment for BIOS */
#define PNP_DS     (GDT_ENTRY_PNPBIOS_DS * 8)	/* data segment for BIOS */
#define PNP_TS1    (GDT_ENTRY_PNPBIOS_TS1 * 8)	/* transfer data segment */
#define PNP_TS2    (GDT_ENTRY_PNPBIOS_TS2 * 8)	/* another data segment */

/* Bottom two bits of selector give the ring privilege level */
#define SEGMENT_RPL_MASK	0x3
/* Bit 2 is table indicator (LDT/GDT) */
#define SEGMENT_TI_MASK		0x4

#define __KERNEL_CS	(GDT_ENTRY_KERNEL_CS * 8)
#define __KERNEL_DS	(GDT_ENTRY_KERNEL_DS * 8)
#define __USER_DS     (GDT_ENTRY_DEFAULT_USER_DS* 8 + 3)
#define __USER_CS     (GDT_ENTRY_DEFAULT_USER_CS* 8 + 3)


/* User mode is privilege level 3 */
#define USER_RPL		0x3
/* LDT segment has TI set, GDT has it cleared */
#define SEGMENT_LDT		0x4
#define SEGMENT_GDT		0x0

/* Bottom two bits of selector give the ring privilege level */
#define SEGMENT_RPL_MASK	0x3
/* Bit 2 is table indicator (LDT/GDT) */
#define SEGMENT_TI_MASK		0x4

#define IDT_ENTRIES 256
#define NUM_EXCEPTION_VECTORS 32
#define GDT_SIZE (GDT_ENTRIES * 8)
#define GDT_ENTRY_TLS_ENTRIES 3
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)





#endif  // __I386_BOOT_SEGMENT_H__
